Crystal oscillator

Abstract

PURPOSE: To provide a crystal oscillator with superior quality or reliability.SOLUTION: A crystal oscillator comprises a first cover body, a second cover body, and a crystal oscillation element. The crystal oscillation element is positioned between the first cover body and the second cover body. The crystal oscillation element comprises a crystal sheet, a first conductive layer, and a second conductive layer. The first conductive layer is positioned on the first surface of the crystal sheet. The second conductive layer is positioned on the second surface of the crystal sheet. The crystal sheet has a groove or opening that penetrates it. The angle between the side wall of the groove or opening and the first surface or second surface is between 60° and 90°.SELECTED DRAWING: Figure 1E

Description

[Technical Field]

[0001] The present invention relates to a crystal oscillator, and more particularly to a crystal oscillator element in which the sidewalls of grooves or openings in a crystal sheet have a specific range of angles. [Background technology]

[0002] A crystal oscillator is an electronic component for generating vibration frequencies, and its manufacturing method generally involves appropriately cutting a corresponding crystal plate to form a suitable groove or opening pattern, followed by packaging or cutting to form a corresponding crystal oscillator element or crystal oscillator.

[0003] However, as electronic products become lighter, thinner, and smaller, the size of the crystal oscillators they contain must also shrink accordingly. However, in the process of forming the grooves or openings in the crystal oscillators, the quality and yield of the crystal oscillators or crystal oscillators are often significantly affected by the shape of the grooves or openings. Therefore, how to improve the quality and reliability of crystal oscillators has become a research topic. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a crystal oscillator that can have excellent quality or reliability due to a corresponding manufacturing process and / or corresponding structural characteristics (for example, a specific range of angles of the sidewalls of the grooves or openings in the crystal sheet). [Means for solving the problem]

[0005] The present invention provides a crystal oscillator with excellent quality or reliability.

[0006] The crystal oscillator of the present invention includes a first cover, a second cover, and a crystal oscillator element. The crystal oscillator element is located between the first cover and the second cover. The crystal oscillator element includes a crystal sheet, a first conductive layer, and a second conductive layer. The first conductive layer is located on a first surface of the crystal sheet. The second conductive layer is located on a second surface of the crystal sheet. The crystal sheet has a groove or opening extending therethrough. An angle of 60° to 90° is formed between the sidewall of the groove or opening and the first or second surface. [Effects of the Invention]

[0007] As described above, the sidewalls of the grooves or openings in the crystal sheet have an angle of 60° to 90°, so that the crystal oscillator including it has excellent quality and excellent reliability in applications. [Brief explanation of the drawings]

[0008] [Figure 1A] 1A to 1C are schematic top views of a method for manufacturing a portion of a crystal oscillator according to a first embodiment of the present invention. [Figure 1B] 2A to 2C are partial cross-sectional schematic views of a method for manufacturing a part of the crystal oscillator according to the first embodiment of the present invention. [Figure 1C] 2A to 2C are partial cross-sectional schematic views of a method for manufacturing a part of the crystal oscillator according to the first embodiment of the present invention. [Figure 1D] 2A to 2C are partial cross-sectional schematic views of a method for manufacturing a part of the crystal oscillator according to the first embodiment of the present invention. [Figure 1E] 2A to 2C are partial cross-sectional schematic views of a method for manufacturing a part of the crystal oscillator according to the first embodiment of the present invention. [Figure 2] FIG. 5 is a schematic cross-sectional view of a crystal oscillator according to a second embodiment of the present invention. [Figure 3A] 10 is a partial cross-sectional schematic view of a method for manufacturing a part of a crystal oscillator according to a third embodiment of the present invention. FIG. [Figure 3B] 10 is a partial cross-sectional schematic view of a method for manufacturing a part of a crystal oscillator according to a third embodiment of the present invention. FIG. [Figure 3C] 10 is a partial cross-sectional schematic view of a method for manufacturing a part of a crystal oscillator according to a third embodiment of the present invention. FIG. [Figure 4] FIG. 10 is a schematic cross-sectional view of a crystal oscillator according to a fourth embodiment of the present invention. [Figure 5] 1 is a schematic top view of a crystal oscillator according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the drawings, the size or appearance of some tissues or film layers may be enlarged, reduced, or exaggerated for clarity. For example, in the subsequent figures, the inclination angle and / or width of a groove or opening may be exaggerated. Furthermore, the numerical values ​​shown in the instructions may include deviations within the range of deviation acceptable to a person with ordinary knowledge in the relevant field. The deviations may be due to one or more standard deviations in the manufacturing or measurement process, or calculation errors caused by other factors such as the number of digits used in the calculation or conversion process, rounding, error propagation, etc.

[0010] In addition, directional terms, such as "up" or "down," used in the description merely refer to the directions of the accompanying drawings. Therefore, unless otherwise specified, the directional terms used are for explanatory purposes only and do not limit the present invention. In addition, to clearly show the directional relationships between different drawings, some drawings exemplarily show corresponding directions using a Cartesian coordinate system (i.e., an XYZ rectangular coordinate system), but the present invention is not limited thereto.

[0011] Fig. 1A is a schematic top view of a method for manufacturing a portion of a crystal oscillator according to a first embodiment of the present invention, and Figs. 1B to 1E are schematic partial cross-sectional views of a method for manufacturing a portion of a crystal oscillator according to the first embodiment of the present invention.

[0012] Referring to FIG. 1A, a quartz crystal plate 119 is provided. The quartz crystal plate 119 can be divided into multiple element regions 118. In subsequent processes, each element region 118 undergoes an appropriate process, resulting in each element region 118 becoming a corresponding quartz crystal oscillator element (e.g., the crystal oscillator 100 shown in FIG. 1D or another similar quartz crystal oscillator element). For simplicity, FIG. 1A does not show all of the element regions 118 one by one. Furthermore, subsequent cross-sectional views (e.g., FIGS. 1B to 1D) will be illustrated or described in terms of a single element region 118.

[0013] In one embodiment, the quartz plate 119 may be a quartz wafer, which may have a corresponding flat or notch, although the present invention is not limited thereto.

[0014] In one embodiment, the thickness of the quartz crystal plate 119 can be adjusted according to the requirements of the subsequent crystal oscillator 100. For example, the thickness of the quartz crystal plate 119 may be approximately 20 micrometers (μm) to 50 μm. Furthermore, the present invention does not limit whether the thicknesses of the various portions of the quartz crystal plate 119 are consistent.

[0015] 1B, a corresponding patterned conductive layer can be formed on the quartz crystal plate 119 (shown in FIG. 1A) by an appropriate method (e.g., plating and lithography). For example, a corresponding first conductive layer 121 can be formed on the first surface 111 of the quartz crystal plate 119, and a corresponding second conductive layer 122 can be formed on the second surface 112 (the lower part of the figure) of the quartz crystal plate 119. That is, the quartz crystal plate 119 can be sandwiched between the first conductive layer 121 and the second conductive layer 122. The layout design of the first conductive layer 121 or the second conductive layer 122 can be adjusted according to the requirements of the subsequent crystal oscillator 100, and the present invention is not limited thereto.

[0016] 1B, a corresponding mask layer 151 can be formed or disposed on the first surface 111 of the quartz plate 119. The mask layer 151 can expose a portion of the first surface 111, making it suitable for a subsequent etching process.

[0017] In one embodiment, the mask layer 151 may be a patterned photoresist layer formed on the quartz plate 119. The patterned photoresist layer may cover the first conductive layer 121 and a portion of the first surface 111 exposed by the first conductive layer 121.

[0018] In one embodiment, the mask layer 151 may be a preformed metal mask, and the pattern of the metal mask may be formed by a suitable method (e.g., laser engraving), and the metal mask may be disposed on the first conductive layer 121 and / or on the portion of the first surface 111 exposed by the first conductive layer 121 by a suitable method (e.g., adhesive).

[0019] 1C-1D, a corresponding dry etching process is used to remove a portion of the quartz plate 119 to form a corresponding groove or opening 130 (shown in FIG. 1D). The groove or opening 130 is formed by removing a portion of the quartz plate 119 from the first surface 111 toward the second surface 112. In this manner, as shown in FIG. 1D, the minimum width of the groove or opening 130 on the first surface 111 (also referred to as the first width W1) can be greater than or equal to the minimum width of the groove or opening 130 on the second surface 112 (also referred to as the second width W2).

[0020] Compared with wet etching processes, dry etching processes are less prone to side etching and undercutting (although they cannot be completely eliminated). Furthermore, compared with wet etching processes, dry etching processes allow the direction or angle of dry etching to be more easily adjusted or controlled by using a corresponding etching agent. In this way, the corresponding dry etching processes can easily control the corresponding angles, making it possible to match the axial angles of different etching portions (i.e., the directions or angles of the imaginary central axes of corresponding relative side surfaces on the cross section). They can also have a better aspect ratio. In this way, the manufactured crystal oscillator 100 can have better quality and / or a better yield. It should be noted that some dry etching processes (e.g., laser ablation and mechanical drilling) do not necessarily require the mask layer 151.

[0021] In one embodiment, the dry etching process may include a reactive ion etching (RIE) process, such as an inductively coupled plasma reactive ion etching (ICP-RIE) process. The etchant used in the reactive ion etching process may include a fluorine-based etchant. Examples of the fluorine-based etchant include, but are not limited to, trifluoromethane (CHF), carbon tetrafluoride (CF), octafluorocyclobutane (CF), sulfur hexafluoride (SF), mixtures thereof, or mixtures of these with other reactive gases or noble gases (e.g., CF / O, SF / Ar, or CF / He). Compared with mechanical drilling and powder blasting processes, reactive ion etching processes are less susceptible to stress and material damage during the etching process, and compared with laser drilling processes, reactive ion etching processes are less susceptible to heat concentration (e.g., the material absorbs laser light, generating heat in a localized area) or material damage during the etching process.

[0022] Referring to FIG. 1D, after forming the corresponding trenches or openings 130, the corresponding mask layer 151 (if present) may be removed by any suitable method.

[0023] With continued reference to FIG. 1D, after forming the corresponding grooves or openings 130, the first plate 191 and second plate 192 can be positioned to sandwich the quartz plate 119 therebetween.

[0024] In one embodiment, there may be suitable circuitry (not shown) on the first plate 191 or the second plate 192, but the invention is not limited thereto. The circuitry may include, but is not limited to, circuitry located on a single side of the plate, circuitry located on two opposing sides, and / or conductive vias passing through the plate. The invention is not limited thereto, as the layout design of the circuitry can be adjusted as desired.

[0025] In one embodiment, the first plate 191 or the second plate 192 can be in direct or indirect contact with the quartz plate 119. For example, a portion of the first plate 191 or a portion of the second plate 192 can be in direct contact with a portion of the quartz plate 119. For example, a corresponding sealing material (not shown) or a sealing ring (not shown) may be provided between the first plate 191 and the quartz plate 119 or between the second plate 192 and the quartz plate 119.

[0026] In one embodiment, the material of the first plate 191 or the second plate 192 may include quartz or other suitable material, but the present invention is not limited thereto. In one embodiment, the size or shape of the first plate 191 or the second plate 192 may be the same as or similar to the quartz plate 119.

[0027] 1D to 1E, by performing a singulation process in an appropriate manner on the structure shown in Fig. 1D, a corresponding crystal oscillator 10 can be constructed. The singulation process described above includes, for example, performing appropriate cutting corresponding to each element region of the crystal plate 119 and the first plate 191 / second plate 192 to form the corresponding crystal oscillation element 100 and first cover body 141 / second cover body 142.

[0028] After the above-described process, the manufacturing of the crystal oscillator 10 of this embodiment is almost completed. However, it should be noted that the manufacturing method of the crystal oscillator 10 of FIG. 1E is not completely limited to the above-described method.

[0029] Referring to FIG. 1E, the crystal oscillator 10 includes a first cover 141, a second cover 142, and a crystal oscillator 100. The crystal oscillator 100 is located between the first cover 141 and the second cover 142. The crystal oscillator 100 includes a crystal sheet 110, a first conductive layer 121, and a second conductive layer 122. The first conductive layer 121 is located on a first surface 111 of the crystal sheet 110. The second conductive layer 122 is located on a second surface 112 of the crystal sheet 110. The crystal sheet 110 has a groove or opening 130 extending therethrough. In cross section (see FIG. 1E), an angle θ between the sidewall 130d of the groove or opening 130 and the first surface 111 or the second surface 112 is between 60° and 90° (although it may be close to 90° but is not 90°). It should be noted that in angle measurement, the first surface 111 or the second surface 112 mentioned above may refer to an imaginary plane extending from it (either the first surface 111 or the second surface 112) or may refer to an imaginary plane parallel to it. Also, the corresponding angle θ can be obtained by direct measurement (e.g., measuring with an optical microscope or an electron microscope after cutting) or indirect estimation (e.g., estimating using trigonometric functions after confirming the positions of the grooves or openings 130 on the first surface 111 and the second surface 112).

[0030] In one embodiment, the angle θ may be close to, but not equal to, approximately 60°, 65°, 70°, 75°, 80°, 85°, 90°, or may be in a range between any two of the values ​​listed above, or a corresponding value within the range between any two of the values ​​listed above.

[0031] In one embodiment, for grooves or openings 130 formed by reactive ion etching, the angle θ may be between 80° and 90° (although it may be close to, but not 90°).

[0032] In one embodiment, the smallest width of the groove or opening 130 on the first surface 111 (also referred to as the first width W1) may be greater than or equal to the smallest width of the groove or opening 130 on the second surface 112 (also referred to as the second width W2). In one embodiment, the second width W2 may be approximately 80% to 100% of the first width W1. In one embodiment, describing a groove or opening 130 formed by reactive ion etching, the second width W2 may be approximately 99% to 100% of the first width W1.

[0033] In one embodiment, the angle between the central axis A of the groove or opening 130 and the first surface 111 or the second surface 112 is between 75° and 90°. In one embodiment, for grooves or openings 130 formed by reactive ion etching, the angle between the central axis A and the first surface 111 or the second surface 112 may be between 83° and 90°.

[0034] In one embodiment, in cross section (see FIG. 1D), the sidewalls 130d of the grooves or openings 130 present essentially corresponding flat surfaces.

[0035] In one embodiment, in a cross section (see FIG. 1D ), the depth of the groove or opening 130 (which may correspond to the thickness T of the quartz crystal sheet 110 forming the groove or opening 130) may be at least about 1.5 times the minimum width of the groove or opening 130, or more. In one embodiment, in a cross section (see FIG. 1D ), the depth of the groove or opening 130 (which may correspond to the thickness T of the quartz crystal sheet 110 forming the groove or opening 130) may be about 6 times the minimum width of the groove or opening 130, or more. In one embodiment, in a cross section (see FIG. 1D ), the depth of the groove or opening 130 is 6 to 10 times the minimum width of the groove or opening 130. In one embodiment, the depth of the groove or opening 130 (which may correspond to the thickness T of the quartz crystal sheet 110 forming the groove or opening 130) may be about 80 μm. In one embodiment, the minimum width of the groove or opening 130 may be about 10 μm to 20 μm.

[0036] In one embodiment, the first cover body 141 and / or the second cover body 142 can have a corresponding recess, which faces and corresponds to the vibration area 115 of the quartz crystal sheet 110.

[0037] In one embodiment, the first cover body 141 and / or the second cover body 142 may have suitable circuitry (not shown) on them, and the above-mentioned circuitry may be electrically connected to the first conductive layer 121 and / or the second conductive layer 122 correspondingly.

[0038] 2 is a schematic cross-sectional view of a crystal oscillator element according to a second embodiment of the present invention. The crystal oscillator 20 of this embodiment may be the same as or similar to the crystal oscillator 10 described above in terms of structure or manufacturing method, so similar structures or parts are denoted by the same reference numerals and descriptions thereof are omitted.

[0039] Referring to FIG. 2, the crystal oscillator 20 includes a first cover 241, a second cover 242, and a crystal oscillator element 200. The crystal oscillator element 200 is located between the first cover 241 and the second cover 242. The crystal oscillator element 200 includes a crystal sheet 210, a first conductive layer 121, and a second conductive layer 122. The first conductive layer 121 is located on a first surface 111 of the crystal sheet 210. The second conductive layer 122 is located on a second surface 112 of the crystal sheet 210. The crystal sheet 210 has a groove or opening 230 extending therethrough. The appearance or cross-sectional shape of the groove or opening 230 may be the same as or similar to the groove or opening 13 described above (e.g., having an angle of 60° to 90°).

[0040] In this embodiment, the material, size, and / or corresponding arrangement method (e.g., circuit related) of the first cover body 241 and / or the second cover body 242 may be the same as or similar to the first cover body 141 and / or the second cover body 142 described above, so detailed description will be omitted here.

[0041] In this embodiment, the thickness of the vibrating region 215 of the crystal sheet 210 is smaller than the thickness of the peripheral region 216 of the crystal sheet 210 .

[0042] In one embodiment, the thickness of the vibration region 215 of the crystal sheet 210 is smaller than the thickness of the peripheral region 216 of the crystal sheet 210, and the first cover body 241 and / or the second cover body 242 have a solid structure similar to a rectangle (i.e., they are not inverted U-shaped, U-shaped, or similar), which reduces the difficulty of bonding. Also, the etching process for forming the grooves can be omitted, which simplifies or eliminates some processes (e.g., groove alignment).

[0043] 3A to 3C are partial cross-sectional schematic diagrams of a method for manufacturing a portion of a crystal oscillation element according to a third embodiment of the present invention. The crystal oscillation element 30 of this embodiment can be the same as or similar to the crystal oscillator 10 described above in terms of structure or manufacturing method, so similar structures or parts are denoted by the same reference numerals and descriptions thereof will be omitted. For example, the manufacturing method for the crystal oscillation element 30 of this embodiment can be carried out by continuing the steps shown in FIG. 1C.

[0044] 1C and 3A, after removing a portion of the quartz crystal plate 119 from the first surface 111 toward the second surface 112, the structure shown in FIG. 1C can be inverted. Then, as shown in FIG. 3A, a portion of the quartz crystal plate 119 is removed from the second surface 112 toward the first surface 111.

[0045] For example, a corresponding mask layer 352 can be formed or disposed on the second surface 112 of the quartz plate 119. The mask layer 352 can expose a portion of the second surface 112, making it suitable for a subsequent etching process.

[0046] It should be noted that the mask layer 351 can be formed at an appropriate step. For example, in the embodiment shown in Figures 1C and 3A, the mask layer 352 can be formed after the step shown in Figure 1C. In an embodiment not shown, the corresponding mask layer 352 can be formed or disposed on the second surface 112 of the quartz plate 119 before removing a portion of the quartz plate 119 (e.g., the step shown in Figure 1C).

[0047] Referring to Figures 3A-3B, corresponding grooves or openings 130 can be formed in a manner similar to that shown in Figures 1C-1D.

[0048] It should be noted that mask layer 351 can be removed in an appropriate step. For example, in the embodiment shown in FIGS. 1C and 3A-3B, mask layer 151 (shown in FIG. 1C) can be removed first, and then mask layer 352 (shown in FIG. 3A) can be removed. In an embodiment not shown, mask layer 151 (shown in FIG. 1C) and mask layer 352 (shown in FIG. 3A) can be removed together in the same step.

[0049] 3B-3C, after forming the corresponding grooves or openings 330, a first plate (not shown, the same as or similar to first plate 191 in FIG. 1D) and a second plate (not shown, the same as or similar to second plate 192 in FIG. 1D) can be positioned and quartz crystal plate 119 sandwiched therebetween in a manner similar to that shown in FIGS. 1C-1D. Thereafter, a corresponding singulation process can be performed to form a corresponding quartz crystal oscillation element 30 in a manner similar to that shown in FIGS. 1D-1E.

[0050] After the above-described processes are performed, the manufacturing of the crystal oscillation element 30 of this embodiment is almost completed. However, it should be noted that the manufacturing method of the crystal oscillation element 30 of FIG. 3B is not completely limited to the above-described method.

[0051] Referring to FIG. 3C, the crystal oscillator 30 includes a first cover 141, a second cover 142, and a crystal oscillator 300. The crystal oscillator 300 is positioned between the first cover 141 and the second cover 142. The crystal oscillator 300 includes a crystal sheet 110, a first conductive layer 121, and a second conductive layer 122. The first conductive layer 121 is positioned on the first surface 111 of the crystal sheet 110. The second conductive layer 122 is positioned on the second surface 112 of the crystal sheet 110. The crystal sheet 110 has a groove or opening 330 extending therethrough. In cross section (see FIG. 3C), an angle θ between the sidewall 330d of the groove or opening 330 and the first surface 111 or the second surface 112 is between 60° and 90°.

[0052] The manufacturing methods for crystal oscillation element 300 and crystal oscillation element 100 are similar, but differ in the formation of grooves or openings 330. Furthermore, structurally, the minimum width of grooves or openings 330 on first surface 111 (also referred to as first width W1) can be made closer to the minimum width of grooves or openings 330 on second surface 112 (also referred to as second width W2). For example, the ratio of first width W1 to second width W2 may be approximately 0.99 to 1.01.

[0053] In this embodiment, the horizontal position of the narrowest portion of groove or opening 330 is located between first surface 111 and second surface 112. In one embodiment, the width W3 of the narrowest portion is approximately 99.5% to 100% of the first width W1 or the second width W2.

[0054] In one embodiment, in cross section (see FIG. 3C), the sidewall 330d of the groove or opening 330 has a first portion 331 near the first surface 111 and a second portion 332 near the second surface 112. The first portion 331 and / or the second portion 332 essentially exhibit corresponding flat surfaces. Briefly, in cross section (see FIG. 3B), the groove or opening 330 may be shaped like an hourglass.

[0055] 4 is a schematic cross-sectional view of a crystal oscillation element according to a fourth embodiment of the present invention. The crystal oscillation element 40 of this embodiment may be the same as or similar to the crystal oscillator 10 described above in terms of structure or manufacturing method, so similar structures or parts are denoted by the same reference numerals and descriptions thereof will be omitted.

[0056] Referring to FIG. 4, the crystal oscillation element 40 includes a first cover 141, a second cover 142, and a crystal oscillation element 400. The crystal oscillation element 400 is located between the first cover 141 and the second cover 142. The crystal oscillation element 400 includes a crystal sheet 110, a first conductive layer 121, and a second conductive layer 122. The first conductive layer 121 is located on the first surface 111 of the crystal sheet 110. The second conductive layer 122 is located on the second surface 112 of the crystal sheet 110. The crystal sheet 110 has a groove or opening 130 extending therethrough. In cross section (see FIG. 4), the angle θ between the sidewall 430d of the groove or opening 430 and the first surface 111 or the second surface 112 is between 60° and 90°.

[0057] The manufacturing method or corresponding structure of crystal oscillation element 400 may be similar to the manufacturing method or corresponding structure of crystal oscillation element 100, except that the angle θ between central axis A and first surface 111 or second surface 112 may be less than 90°. This may occur (but the present invention is not limited to this) when the etching target is placed in an inclined direction during the formation of groove or opening 430, but this does not have any significant effect on the structure and / or corresponding use of crystal oscillation element 400.

[0058] 5 is a schematic top view of a portion of a crystal oscillation element according to one embodiment of the present invention, specifically, a corresponding crystal oscillation element.

[0059] The crystal oscillator 50 includes a first cover (not shown, which may be the same as or similar to the first cover 141 or 241 described above), a second cover (not shown, which may be the same as or similar to the second cover 142 or 242 described above), and a crystal oscillator element 500. Similar to the cross-sectional view described above, the crystal oscillator element 500 is located between the first cover and the second cover. The crystal oscillator element 500 includes a crystal sheet 110, a first conductive layer 121, and a second conductive layer 122. The crystal sheet 110 includes a vibrating region 115 and a peripheral region 116. When viewed from above (e.g., as shown in FIG. 5 ), a groove or opening 530 may be located between the vibrating region 115 and the peripheral region 116. The first conductive layer 121 is located on a first surface 111 of the crystal sheet 110. The second conductive layer 122 is located on a second surface 112 of the crystal sheet 110. The quartz crystal sheet 110 has a groove or opening 530 penetrating therethrough. Furthermore, a cross section of the quartz crystal oscillation element 500 taken along the A-A' cross section may be as shown in FIG. 1D, 2, 3B, or 4. A cross section of the quartz crystal oscillation element 500 taken along the B-B' cross section may be as shown in FIG. 1E, 2, 3C, or 4, corresponding to the groove or opening on one side. That is, the contours of the sidewalls 530d of the groove or opening 530 can be essentially identical in different directions (the direction along the A-A' cross section and the direction along the B-B' cross section). That is, the surface of the sidewalls 530d of the groove or opening 530 is essentially not directly related to the lattice plane of the quartz crystal sheet 110.

[0060] As described above, in the crystal oscillator of the present invention, the sidewalls of the grooves or openings in the crystal sheet have angles of 60° to 90°, so the crystal oscillator has excellent quality and excellent reliability in applications. [Industrial Applicability]

[0061] The crystal oscillator of the present invention can generate an oscillation frequency and can be applied to electronic products such as, but not limited to, communication, information, and consumer electronics. [Explanation of symbols]

[0062] 10, 20, 30, 40, 50 Crystal Oscillator 100, 200, 300, 400, 500 crystal oscillator 119 Crystal plate 118 Element Area 110 Crystal Sheet 111 1st surface 112 Second surface 115, 215 vibration area 116, 216 surrounding area 121 First conductive layer 122 Second conductive layer 151, 352 mask layer 130, 230, 330, 430, 530d Groove or opening 130d, 230d, 330d, 430d, 530d side wall 331 Part 1 332 Part 2 141, 241 First cover body 142, 242 Second cover body 191: First Plate 192 Second Plate W1 1st width W2 Second width W3 Width at narrowest point θ angle A Intermediate shaft T Thickness

Claims

1. A first cover body; A second cover body; Located between the first cover body and the second cover body, Crystal sheet and a first conductive layer located on a first surface of the quartz crystal sheet; a second conductive layer located on a second surface of the quartz crystal sheet; a crystal oscillation element including: wherein the quartz crystal sheet has a groove or opening extending therethrough, and an angle between a sidewall of the groove or opening and the first surface or the second surface is between 60° and 90°.

2. 2. The crystal oscillator according to claim 1, wherein the groove or opening is formed by dry etching.

3. 2. The crystal oscillator according to claim 1, wherein an angle between the central axis of the groove or opening and the first surface or the second surface is 75° to 90°.

4. 2. The crystal oscillator of claim 1, wherein the contours of the sidewalls of the grooves or openings match on different cross sections.

5. 2. The crystal oscillator according to claim 1, wherein the depth of said groove or opening is 1.5 times or more the minimum width of said groove or opening.

6. 2. The crystal oscillator according to claim 1, wherein the width of the groove or opening in cross section gradually increases from the second surface toward the first surface.

7. 2. The crystal oscillator according to claim 1, wherein the sidewalls of the grooves or openings are flat in cross section.

8. 2. The crystal oscillator according to claim 1, wherein the horizontal position of the narrowest portion of said groove or opening is located between said first surface and said second surface.

9. 2. The crystal oscillator of claim 1, wherein the sidewall of the groove or opening has a first portion near the first surface and a second portion near the second surface, the first portion and the second portion presenting corresponding flat surfaces.

10. 10. The crystal oscillator according to claim 8, wherein the groove or opening is formed by a dry etching method performed multiple times.

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